N. E. El-Bassiouni

Immunohistochemical expression of CD95 (Fas), c‐myc and epidermal growth factor receptor in hepatitis C virus infection, cirrhotic liver disease and hepatocellular carcinoma

Gene product expression in normal and chronic hepatitis C virus infection was determined in an attempt to improve our understanding of the molecular events leading to the development of cirrhosis and liver carcinoma. Activation of CD95 (Fas) causes apoptosis of cells and liver failure in mice and has been associated with human liver disorders. c‐myc is involved in cell proliferation and EGFR in regeneration of cells. The material of the current study included 50 cases of chronic hepatitis C (CHC) (and negative hepatitis B virus infection), 29 cases of liver cirrhosis and HCV (LC), and 19 cases of hepatocellular carcinoma and HCV (HCC) admitted to the Theodor Bilharz Research Institute (TBRI) during the years 2003–2004. Ten wedge liver biopsies – taken during laparoscopic cholecystectomy – were included in the study as normal controls. Laboratory investigations, including liver function tests, serological markers for viral hepatitis and serum alpha fetoprotein level (α‐FP), were determined for all cases. Histopathological study and immunohistochemistry using monoclonal antibodies for CD95, c‐myc and EGFR were also done. In CHC cases, the histological activity index (HAI) revealed more expression of Fas antigen in liver tissues with active inflammation than in those without active inflammation (p<0.01). EGFR and c‐myc act synergistically in liver tumorigenesis. Upregulation of Fas in chronic hepatitis C infection and of c‐myc & EGFR in malignant transformation was concluded from this study. c‐myc expression may obstruct the induction of apoptosis of HCC cells and lead to uncontrolled cell growth.

The coagulation profile in hepatosplenic schistosomiasis

The biological activity of blood coagulation factors II, V, VII, VIII, IX, X, XI and XII, fibrinogen and prekallikrein was assessed in 15 healthy subjects and 60 patients with endemic Egyptian hepatosplenomegaly. The degree of liver disease was graded according to the Child-Pugh classification, the intensity of S. mansoni infection was monitored by determination of circulating schistosome immune complexes (CSIC) level using a monoclonal antibody and hemostasis activation was detected by measurement of hemostatic markers D-dimer and prothrombin fragment 1 + 2 (F1+2). Functional activity of antithrombin III, alpha2-antiplasmin and protein C as well as quantitative determination of plasma concentrations of alpha1-antitrypsin, C1 activator inhibitor and alpha2-macroglobulin were also carried out. The progressive deterioration of liver function which matched the severity of the disease and the intensity of schistosomal infection led to a reduction in anticoagulant proteins (decreases in antithrombin III and protein C) resulting in hypercoagulability and thrombin generation (increased F1+2) subsequently followed by consumption (prolongation of coagulation screening tests, thrombocytopenia, hypofibrinogenemia and decreased factor VIII resulting in hypocoagulability and secondary fibrinolysis (increased D-dimer and decreased alpha2-antiplasmin). A significant decline in fibrinogen and factors VII, XII and prekallikrein was detected in bleeders compared with ascitic patients. The decline in factor XII was closely related to CSIC high titers in all disease groups, but was not correlated to D-dimer or F1+2 concentrations. This suggests that circulating schistosome immune complexes may exert an inhibitory effect on contact factor XII which should be taken into account when considering the reasons for schistosomal coagulopathy and bleeding in hepatosplenic schistosomiasis.

Hyperfibrinolysis in hepatosplenic schistosomiasis.

AIM: To evaluate the nature of accelerated fibrinolysis in hepatosplenic schistosomiasis. METHODS: The biological activity of plasminogen (Plg), plasminogen activators (PA), alpha 2-antiplasmin (alpha 2-AP) and plasminogen activator inhibitor-1 (PAI-1) was determined by photometric analysis in 15 compensated and 35 decompensated patients with endemic Egyptian hepatosplenomegaly. Quantitative measurement of plasma concentrations of tissue t-PA, t-PA-PAI-1 complex, alpha 2-antiplasmin-plasmin complex (alpha 2-APP), fibrinogen degradation products (FbDP), D-dimers (D-D), thrombin-antithrombin complex (TAT) and prothrombin fragment (F 1 + 2) complexes, using double antibody sandwich enzyme linked immunosorbent assays and grading of the degree of hepatic insufficiency according to the Child-Pugh classification, were also carried out. RESULTS: The progressive deterioration of liver function in schistosomal patients, which matched the severity of the disease, led to simultaneous defects in profibrinolytic (decreased Plg and increased PA and t-PA) and antifibrinolytic (decreased alpha 2-AP and PAI-1) factors-the latter defects being the most prominent-resulting in significant generation of plasmin (increased APP complexes) and therefore enhanced fibrinolysis (increased FbDP and D-dimer). The raised concentrations of FbDP, D-D, TAT and F 1 + 2 established its secondary nature. CONCLUSION: These findings suggest that the amount of PAI-1 available to bind and neutralise circulating t-PA may be a critical factor in the progress of hyperfibrinolysis observed in hepatosplenic schistosomiasis, and that the pronounced reduction in its plasma concentration may be regarded as a potential warning indicator of haemostatic imbalance in decompensated schistosomal patients at high risk of variceal bleeding.

Fibronectin, Platelet Factor 4 and Beta-Thromboglobulin in Endemic Hepatosplenic Schistosomiasis: Relation to Acute Hematemesis

Some platelet alpha-granule contents were assessed in parallel with other markers of hemostatic imbalance in 50 patients with hepatosplenic schistosomiasis (15 patients with compensated hepatosplenomegaly, 15 patients with advanced hepatic fibrosis and ascites and 20 patients during an acute attack of hematemesis from ruptured esophageal varices). Platelet factor 4 (PF4), beta-thromboglobulin (beta-TG), fibronectin (FN), prothrombin fragment 1 + 2, thrombin-antithrombin (TAT) complexes, fibrin degradation products (FbDP) and D-dimer were assessed in schistosomal patients compared to controls (15 healthy subjects). A significant increase in both thrombin (high TAT and prothrombin fragment 1 + 2 levels) and plasmin (high FbDP and D-dimer levels) generation was detected in decompensated patients establishing the presence of a steady state of low-grade disseminated intravascular coagulation, with and without overt bleeding, in these patients. A decrease in plasma FN concentration was found in diseased groups compared to controls. The reduction in plasma levels of FN paralleled the defective liver function and matched the relative decrease in tissue FN in liver specimens of decompensated patients suggesting that FN levels can be used to evaluate the pathological staging of the disease. A significant increase in beta-TG and PF4 levels was noted in decompensated patients with ascites and/or acute hematemesis compared both to controls and compensated patients reflecting platelet alpha-granule release and consequently increased in vivo platelet activation which may initiate and/or perpetuate the pathophysiological mechanisms of the hemostatic imbalance underlying the hemorrhagic diathesis in hepatosplenic schistosomiasis.

Tissue factor expression on blood monocytes in patients with hepatitis C virus-induced chronic liver disease

Chronic liver disease (CLD) is a worldwide common pathology characterised by an inflammatory and fibrotic process leading to progressive evolution from chronic hepatitis to cirrhosis. Monocytes play a crucial role in the pathogenesis of inflammation and fibrosis in chronic liver diseases. Activated monocytes increase the expression of tissue factor, a key glycoprotein that participates in haemostatic and inflammatory processes. This study aims to assess the expression of tissue factor on activated peripheral blood monocytes in patients with hepatitis C virus (HCV)-induced CLD in relation to the degree of hepatic insufficiency and haemostatic imbalance. The current study included 60 patients with HCV-induced CLD, categorised after Child–Pugh into four groups: Child A, B, C and C during acute attack of haematemesis, 15 patients each, and 15 healthy subjects were included as normal controls. Immunophenotype characterization was carried out by flow cytometric analysis for identification of monocytes tissue factor expression (CD142) on activated blood monocytes population (CD11b and CD14) in different groups studied. Data demonstrated significant increase (p < 0.05) in the expression of each of CD11b, CD14 and CD142 revealing monocytes activation and increased expression of tissue factor on peripheral blood monocytes in different groups of patients especially cases during acute attack of haematemesis, compared to healthy subjects. Increased monocytes tissue factor expression in patients with HCV may play a key role in the intensification of the inflammatory and immunological processes in conjunction with activation of the coagulation mechanisms. The interaction of all these phenomena may trigger bleeding by perturbing the unstable haemostasis in frail patients with chronic liver disease.